Demonstrating-model.



PATENTED SEPT. 19, 1905.

C. MELROSE. DEMONSTRATING MODEL.

APPLICATION FILED OCT. 12, 1904.

Li M 14 Witnesses.-

0 4m WW.

CHARLES MELROSE, OF SAN FRANCISCO, CALIFORNIA.

DEMONSTRATlNG-IVIODEL.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed October 12, 1904. Serial No. 228,234.

To mi] whom it TH/CI/I/ concern:

Be it known that I, CHARLES MuLRosn, a citizen of the United States of America, residing at San Francisco, county of San Francisco, and State of California, have invented certain new and useful Improvements in Demonstrating-Models; and I hereby declare the following to be a full, clear, andexactdescription of the same, reference being bad to the accompanying drawings, forming a part of this specification.

This invention relates to demonstratingmodels to illustrate by certain adjustments the mode of operating and the functions of distributing-valves for steam-engines actuated by what is technically called link-gearing,as hereinafter described, and illustrated by diagrammatic drawings forming a part of this specification.

My invention consists in patterns or models of the various operating parts of a steam-em gine connected and operative to show the movements and relation of the various parts in their relative positions, the whole made preferably of thin metallic plates mounted on a plate or other suitable plane surface convenient to handle and durable in its nature.

The objects of my invention are educa tional, to instruct students and apprentices in the art of designing, operating, and making valve-gearing, and to enable practical steam engineers to perform the various adjustments in valve-gearing in a correct manner.

Referring to the drawings, Figure I is a plan view of ademonstrating-model with simple link-motion constructed and arranged according to my invention. Fig. II is an edge view of the device shown in Fig. I. Fig. III is a plan view of the same general features as Fig. I, but with the link suspended in a man ner that permits adjustment to compensate .the angularity of the connecting-rod; and

Fig. IV, an edge view of the device shown in Fig. III with screw 24Coinitted.

The several parts are indicated by reference-numerals as follows.

1 represents the engine-cylinder; 2, the piston; 3, the piston-rod; 4, the cross-head; 5, the cross-head guide; 6, the connecting-rod; 7, the crank-wheel; 8 and 9, the eccentrics; l0 and 11, eccentric-rods; 12, the link; 13, the distributing or slide valve; 14, the valverod; 15, a lever that reverses the motion of the link and valve relatively; 16 and 17, devices for suspending and adjusting the link; 19, a plate on which the parts are mounted;

20 and 21, induction ports or passages; the eduction-port.

All the various joints in the model requiring adjustment are movable and provided with slots and clamping-screws as follows: the eccentrics 8 and S) by the screw 23, the link in Fig. I by the screw 24., the valve 13 by the screw 25, the eccentric-rod by the screws 26, the link-hanger by the screw 27.

The crank-wheel 7 is marked, as shown, at ninety degrees of are to indicate dead-centers andquarters ofstroke; also, may have further divisions, if required; The cross-head slides 5 and cylinder 1 havedivisions or indicationpoints marked thereon, such as are required in practice to determine, with the adjustments, the following functions: the effect of outside and inside lap of distributing-valves; steam distribution as affected by the angularity of the connecting-rod; points of admission and cut-off in respect to the position of the piston and stroke; expansion and compression so far as controllable by a single distributing-valve; the position or angle of advance for eccentrics; the effect of sus 'iending a link outside of its central are or offsetting the saddle-pin, as it is technically termed; adjustment of the link in respect to crankshaft center; also, various other problems connected with steam distribution by a single valve.

It will be obvious that the slide-valve13 can be arranged for outside or inside ad mission of steam, the lap being provided for accordingly; also, that the action is the same whatever be the form of the valve-faces.

In operating the adjustments are permitted by the several movable joints, the clfect being obvious except as to the screw 27 in Figs. III and IV, dealing with the angularity of the connecting-rod. This latter adjustment produces a circular movementof the body of the link 12 on an arc the radius of which is the distance of the pivot or screw 27 from the central line of the link 12, but modified by the position of the link, and as a graphic or computed problem is intricate, but can be clearly demonstrated by the present model.

The eccentrics 8 and 9 are loosely mounted on the crank-shaft and independently adjustable about the center thereof, so as to be readily adjusted to any desired position relatively and are clamped by the screw 23 when adjusted. This forms an important feat of my invention and enabhgs various experiments to be made in demonstra jects of my invention, what I claim as new, \\'hile revoluble, substantially as Speeilierl. and desire to secure by Letters Patent, isin testimony whereof l hnrcsigned my name The herein-described model for educational to this specification in the presenceol' two sub- Having thus explained the nature and obi clamping them in (lill'erent relative positions 10 5 use, consisting of thin plates representing the scribingwitnesses.

various parts of a link-motion steam-engine, ClilAl-lLES MELROSE. movnbly and adjust'ably connected together, \Vitnesses:

the eccentrics being independently revoluble ELMER Wronnis,

about the crank-shaft center, with means for IXLl-l-tl-Jl.) A. .liNQUl-S'l. 

